NASA has been studying the region around the Earth which protects us from the solar wind. A unique group of five satellites, called THEMIS, are helping scientist to unlock the mystery of how Earth's magnetosphere stores and releases energy from the sun. Three of these satellites continue to study substorms that are visible in the Northern Hemisphere as a sudden brightening of the Northern Lights, or aurora borealis.
Two of the five spacecraft have been sent on a new mission to the moon. This mission is called ARTEMIS, or Acceleration, Reconnection, Turbulence and Electrodynamics of Moon's Interaction with the Sun. As the name suggests, the two spacecraft will measure what happens when the Sun’s radiation hits our rocky moon, where there is no magnetic field to protect it.